1. Field of the Invention
Embodiments of the invention relate to a solar cell, a method of manufacturing the same, and a solar cell module including a plurality of solar cells.
2. Description of the Related Art
Recently, as existing energy sources such as petroleum and coal are expected to be depleted, interests in alternative energy sources for replacing the existing energy sources are increasing. Among the alternative energy sources, solar cells generating electric energy from solar energy have been particularly spotlighted.
A solar cell generally includes a substrate and an emitter layer which are respectively formed of different conductive type semiconductors, for example, p-type and n-type semiconductors. In this case, the emitter layer is positioned in a light receiving surface of the substrate, and a p-n junction is formed at an interface between the substrate and the emitter layer. A plurality of first electrodes electrically connected to the emitter layer is positioned on the emitter layer, and a plurality of second electrodes electrically connected to the substrate is positioned on a surface opposite the light receiving surface of the substrate.
When light is incident on the solar cell, electrons inside the semiconductors become free electrons (hereinafter referred to as “electrons”) by the photoelectric effect. Further, electrons and holes respectively move to the n-type semiconductor (e.g., the emitter layer) and the p-type semiconductor (e.g., the substrate) in accordance with the principle of the p-n junction. The electrons moving to the emitter layer and the holes moving to the substrate are respectively collected by the first electrodes and the second electrodes respectively connected to the emitter layer and the substrate.
At least one current collector, for example, at least one bus bar is positioned on each of the substrate and the emitter layer. The current collector on the substrate and the current collector on the emitter layer are electrically connected to the second electrodes on the substrate and the first electrodes on the emitter layer, respectively.
However, a light receiving area of the solar cell having the above-described configuration decreases because of the first electrodes on the emitter layer and the at least one bus bar for electrically connecting the first electrodes.